Polygynandry and the Alpine Accentor

Sharon has 3 children, sired by either Corey, Mike or Kenn**; but she is not that concerned because Dawn suspects that her 17 little ones might not only have been from these three young males, as there were also many visits by Jochen and many a pleasant afternoon spent with Charlie, who now lives in another area. Dawn and Sharon are neighbours, but the males move freely through and between the two areas. And their Facebook status is always stuck on “its complicated” – a stable marriage of three males and two females. Nice.

((** all names have been changed to protect identities and have been substituted with (almost) randomly chosen substitutes suitable for a family of Alpine Accentors.))

Over the next few days, the Alpine Accentors (Prunella collaris) will arrive on their high-Alpine breeding grounds – it is time to start singing, despite that the treeless Alpine landscape is still under metres of snow. At first, they seem to “stage” in the general area of their breeding territories, feeding in skiing resorts or anywhere else where the snow is a little more open and food is a little more available. Over the next month, they will spend more and more time singing in their breeding territories, and travelling to feed in other areas, up until they can find enough food within their territories:

typical Alpine Accentor (Prunella collaris) habitat at breeding time

So you have probably come across cases of Polygyny (one male, multiple females), as in the case of lions, Red-winged Blackbirds or Northern Harrier; and you may even have heard of a few cases of Polyandry (one female, multiple males), such as Red Phalarope and many Jacanas.

Now Alpine Accentors have a much more interesting strategy: 3-5 males defend a single breeding territory, containing 2-3 spatially separated female Accentors. All individuals in this Polygynandrous relationship may mate with each other, but more dominant males will typically have greater access to females.

Here are two really interesting papers on the fascinating private lives of Alpine Accentors, if you would like to read a little more:

and the “lowland” accentor: Dunnock (Prunella modularis) (Davies, Hartley, Hatchwell & Langmore 1996 and references therein). I cannot seem to find any evidence that any of the other accentors are polygynandrous; at least some of them seem not to be.

If you know or hear of other examples, please let me know and I will add them to this list.

Dale got his first pair of binoculars for a very early birthday after his dad realized that it was the only way to be left in peace. Many robins, eagles and finches later, he ended up at university studying various biology things and wrote a thesis on vertebrate biogeography in southern African forests. While studying, he also worked on various conservation/research projects (parrots, wagtails, vultures, and anything else that flew) and ringed thousands of birds. Dale studied scarlet macaws, and worked in their conservation, for three years in southern Costa Rica, followed by a year in the Caribbean working on Whale Sharks. After meeting the woman of his dreams, he moved to Austria where he now has the coolest job in the world making awesome toys for birders (Swarovski Optik product manager). He happens to also be obsessed with photography, particularly digiscoping, and despite all efforts will almost certainly never be a good birder. He also blogs for birdingblogs.com

@Corey, Is there also a Daisy involved in this Group Marriage? We are now up to 3 males and at least 4 females (I see there is a Kim in the group photo too). These group dynamics are always hard to track, but this group seems particularly complex.

€Dawn, you are looking coy in you profile photo. Any reason?

@yourbirdoasis, I added a list of some examples which I had found. If you hear of any others, please let me know and I will add them.

@Duncan, they would only be licentious if one thought Group Marriage to be bad.

@Jogi, is that Jochen the accentor or Jochen the person trying to arrange a hook-up?

I remember having read the excellent book from Alexandra David-Néel, who was the first european woman to travel to Lhassa in Tibet, in the 1920’s. She described in her book “My Journey to Lhasa” (1927) how, in the rugged mountain of tibet, women were commonly married to 2 men (sometimes brothers), making it easier (or simply possible?) to have and raise children.

Should we see a parallel between the alpine accentor and traditional populations of the highest mountains in the world? Do all the males provide food for the few nests, increasing the chance for all of them to transmit their DNA to the next generations?

Hi Laurent, that is a fascinating example of humans responding to difficult environmental challenges. In this case, they would be exhibiting polyandry. Might I assume that women typically bear fewer children, or fewer survive? (i.e. small families putting less pressure on the adult members of the family).

So polygynandry really is rare, but I can’t believe I forgot about Acorn Woodpecker! Not only is it rare, but taxonomically all over the map. I’m guessing that there are a lot more polygynandrous species than we realize, but that we just haven’t discovered it yet due to the combination of still fairly recent advances in genetic techniques to asses breeding systems and only a handful of researchers doing this sort of work.

@yourbirdoasis, I think one of the problems in showing polygynandry is individual identification and figuring out the complexities of the interactions. From what I understand, polygynandry is typically separated from promiscuity in that the individuals in the former are typically in some sort of bond with the other individuals (Group Marriage, to use an anthropomorphism) as opposed to sleeping around (to use another anthropomorphism).
In the case of Acorn Woodpeckers, they are cooperative breeders (as with many other polygynandrous species), which seems to predispose species to polygynandry. Cooperatively breeding species tend to have a strong alpha-pair + helpers structure with occasional beta males/females getting involved in the gene flow process.
Alpine Accentors, on the other hand, are not cooperative breeders and females typically have very little to do with each other.
All of this is just my understanding of it – I would love to be corrected by someone who knows better. In fact, that gives me an idea; maybe I should do something of an interview with a cooperative breeding specialist. That would be mighty interesting.

@Jochen, if you helped make them, you gotta take care of them!

@Laurent, I cannot find anything on White-throated Sparrows being polygynandrous. Do you know of any references for this?

Thanks Dale, I am inclined to believe that you are right on all counts. There is much more of a ‘social structure’ that helps to characterize polygynandrous speices from those that are more obviously promiscuous. I think if you were interested in studying an unknown polygynandrous species, you might start by looking at species assumed to be promiscuous. You are also right about cooperative breeding as a sort of preadaptation (if you will) for the evolution of polygynandry from promiscuity.

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